This invention relates to a scroll compressor having a retainer for a discharge check valve.
One popular type of modern compressor is a scroll compressor. A scroll compressor includes a pair of scroll members each having a base and a generally spiral wrap extending from the base. The wraps of the two scroll members interfit to define compression chambers. One of the scroll members is driven to orbit relative to the other. During this orbital movement, the compression chambers decrease in volume to thereby compress refrigerant within the chambers.
Compressors are typically mounted within a sealed container. For such compressors, the pump unit for compressing the refrigerant is positioned at one end, and a motor for driving the pump unit is positioned at another end. Often the suction pressure refrigerant is allowed to circulate over the motor for cooling. Consequently, it becomes necessary to separate a suction pressure chamber from a discharge pressure chamber.
In traditional scroll compressors, the non-orbiting scroll does not seal against the compressor housing. Instead, a separate plate is positioned outwardly of the base of the non-orbiting scroll to separate the housing into suction and discharge pressure chambers. Most typically, a discharge pressure chamber is formed above the separator plate, and the area below the separator plate is at suction pressure.
More recently, it has been proposed to incorporate the separator function into the base of the non-orbiting scroll. In such compressors, the base of the non-orbiting scroll is sealed to the housing. Thus, there is the discharge pressure chamber on one side of the base of the non-orbiting scroll and the suction pressure chamber on the other.
For the foregoing conventional designs, refrigerant from the suction chamber is compressed in the compression chambers and typically passes through a check valve, to the discharge pressure chamber. Typically, as shown by FIG. 8, the check valve is retained by a valve retainer, such as valve retainer 204, within valve chamber 206 of non-orbiting scroll member 200. To permit compressed refrigerant to pass from valve chamber 206 to a discharge pressure chamber, the non-orbiting scroll member 200 is provided with gas passages 208, which are machined into the non-orbiting scroll member 200. Valve retainer 204 is lodged between the gas passages 208 of valve chamber 206 by press fitting the retainer 204 on the edges of the gas passages 208.
The above design, while successful, does carry some challenge to manufacture. Specifically, because valve retainer 204 is press fit between the gas discharge passages 208, valve chamber 206 must be machined with great precision. However, machining valve chamber 206 is difficult and time consuming. Accordingly, manufacturing the current assembly may sometimes result in rejected parts.
A need therefore exists for an improved design for the valve retainer that avoids the time consuming process of machining the non-orbiting scroll and easily allows retention of the compressor's check valve.